* Alkali metals (Group 1): These metals have only one valence electron, making them very eager to lose it and form a +1 ion. This makes them extremely reactive, especially with water. Examples include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
* Alkaline earth metals (Group 2): These metals have two valence electrons, which they readily lose to form +2 ions. They are less reactive than alkali metals but still highly reactive. Examples include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
